Rotating high-pressure spray head and optional drill

ABSTRACT

A high-pressure water spray gun is disclosed for use, for example, for fire-fighting. The spray gun has a cylindrical body for connection to a supply hose and a spray lead rotatable in the body by water issuing through pairs of jet nozzles around the barrel of the spray head. In each pair of nozzles, the axes of the nozzles are convergent and being closest to each other in a mixing region at, or just outside of, the outer surface of the barrel. At least one nozzle has a non-radial axis. The spray head may be normally housed in the body, being moved to an exposed working position by water pressure against a spring.

This invention relates to spray heads for converting a liquid at highpressure into an enveloping spray around the head. Such a spray head mayfor instance form part of a high-pressure spray gun, for example a waterspray gun for extinguishing fires. The invention also relates tohigh-pressure spray guns incorporating such a spray head.

Many different types of spray head are known, one example being the typeof garden or agricultural sprinkler that has a rotating arm having jetnozzles at its ends. The arm is rotated by water pressure so that waterIs sprayed over a circular area around the sprinkler. At any givenmoment, a given point in this area may not be under the water, whichmoves in a circle.

Another type of sprinkler has a head that has jet nozzles distributedaround a circumferential surface to produce a continuous water spray.

An object of the present invention is to provide a spray head, and/or aspray gun, that gives an intense spray of substantially atomisedparticles of water or other liquid within a space around the spray head,such as not merely to deposit the water on the ground or floor, but tofill the space to a substantial extent. This is important, inparticular, in connection with fire-fighting, but the invention is notconfined to such applications: it can for example find application inprocess industries where the above space-filling facility may be ofadvantage.

According to the invention in a first aspect, a spray head forconverting a liquid at high pressure into an enveloping spray around thehead, is characterised in that it comprises a hollow cylindrical shellhaving a barrel portion of circular cross section, the head having atleast one bearing surface for mounting it for rotation about its axis,the head having means substantially closing it ahead of the barrelportion when so mounted, but being open axially behind the barrelportion for receiving the high-pressure liquid within the latter, thebarrel portion having groups of jet orifices arranged around itscircumference and formed through its wall , each group comprising atleast two orifices having generally convergent axes orientated so as tobe closest to each other in a mixing region at or Just outside the outercylindrical surface of the head, and the axis of at least one orifice ineach group being non-radial.

Preferably, at least one said group includes an orifice so orientated asto direct a Jet of liquid in a direction such as to cause the head torotate about its own axis.

At least one said group preferably comprises orifices arranged to passliquid through them at different flow rates.

According to the invention in a second aspect, a spray gun ischaracterised by a hollow body adapted for connection to a high pressureliquid supply, the body being open at its downstream end and havingmounting means carrying a spray head according to the said first aspectof the invention, the spray head being sealingly engaged in the body.

Preferably, the spray gun has a body in the form of a cylinder or tube,connectable at its rear end to a source of a fluid under pressure andopen at its front end. The spray head may then be a piston housedcoaxially in the body, and spring means for biassing the piston towardsthe rear so that it normally lies substantially wholly within the body.

The mounting means may then be a shaft, arranged coaxially With the tubeand projecting sealingly out through the front part of the piston. Thisshaft is rotatable in the tubular body and is hollow, projecting beyondthe front end of the body and, optionally, terminating in a jet nozzle.The shaft is preferably arranged to be driven in rotation, by anysuitable drive means.

The shaft can even carry at its leading end a drill of approximately thesame outer diameter as the cylinder containing the piston, this drillbeing adapted for drilling through a wall or other part of a building bytrepanning; the leading end of the hollow shaft lies within the drill.

The jet nozzles of the spray head are so arranged that the liquid forcedunder pressure through the nozzles exerts a resulting turning moment onthe spray head so as to rotate it about the axis of the piston.

Embodiments of the invention will now be described, by way of exampleand with reference to the accompanying drawings, in which:

FIG. 1 is a much simplified, part sectional elevation of part of a fireextinguishing spray gun in one embodiment of the invention:

FIG. 2 is a similar view of part of a spray gun in another embodiment:

FIG. 3 is a partial elevation of a spray head comprising a piston, inone form of the invention, for incorporating in the spray gun of FIG. 2;

FIG. 4 is a partial view seen in diametral cross section in the samedirection as FIG. 3, except for a small scrap section indicated at A inFIG. 4;

FIG. 5 is a scrap cross section on a much larger scale, taken on theline V--V in FIG. 3 and showing a group of jet nozzles:

FIG. 6 is a diagram illustrating features of the geometry of the jetnozzles:

FIG. 7 an outside view, seen looking in a generally radial direction, onanother pair of jet nozzles:

FIG. 8 illustrates a typical use for the spray gun;

FIGS. 9 to 11 show typical uses for the spray gun when modified by theaddition of a trepanning drill; and

FIG. 12 is a much simplified, part-sectional elevation of a fireextinguishing spray gun having such a drill.

FIG. 1 shows part of a spray gun comprising a generally cylindrical body1, with connecting means, not shown, for coupling its rear or posteriorend 112 to the outlet end of a fire hose indicated in phantom lines at110. Part-way along the body 1, a set of radial ribs 114 carries a boss116 to which a coaxial mounting bar 104 is secured. The bar 104 projectsforward through the forward or anterior end 118 of the body 1, andterminates in an end stop 120.

A spray head 50 comprises a hollow cylindrical shell closed at its frontend by a radial wall 52, having a central hole 53 with a bearing surface100 rotatably mounted on the bar 104. The posterior or near end 122 ofthe head 50 has an external, cylindrical bearing surface 102 carrying alabyrinth seal 56 and rotatably fitting in the bore 108 of the forwardend 118 of the body 1.

The spray gun in FIG. 2 differs from that of FIG. 1 in that the bar 104is replaced by a longer bar 106 having a stop element 124. The forwardend portion 118 of the body 1 is also elongated so that the spray head50 lies wholly within it when in the position of the head 50 shown infull lines, which is a "parked" position. When full water pressure isapplied (from the left as seen in FIG. 2), the head 50 acts as a pistonand is driven partly out of the body, so that its barrel portion 54projects from the body, with a light return spring 19 then beingcompressed between the spray head wall 52 and the fixed end stop 120.When the water pressure is reduced or removed, the spring 19 urges thehead 50 back into the body 1 until the wall 52 comes into engagement onthe stop element 124.

Referring now to FIGS. 3 and 4, the hollow cylindrical shell of thespray head 50 has a front end portion 51 which incorporates thetransverse wall 52 with its front bearing 100. The wall 52 closes thefront end of the piston , except for the central hole 53 in the wall 52to accommodate the bar 104 or 106, FIGS. 1 and 2. Behind the portion 51,the cylindrical barrel portion 54 leads to a rear portion 55 whichcarries the bearing surface 102 with its external labyrinth 56, toreduce the pressure drop along the outside of the piston within the body1, in which the outer cylindrical surface 57 of the barrel 54 is a snugsliding and rotating fit.

The barrel 54 has groups of jet orifices (referred to in the rest ofthis description as "nozzles", for convenience), which are arrangedaround its circumference, extending through the barrel wall. Thesegroups may be disposed in any desired way, but in this example they arearranged in two sets, namely a rear set 58 and a front set 59, thegroups of nozzles in each set having the same relationship to arespective diametral plane 60, 61. The rear set 58 consists of eightgroups 62 of nozzles, equally spaced circumferentially. The front setalso consists of eight groups 63 of nozzles, again equally spacedcircumferentially but offset circumferentially by 22 1/2 degrees fromthe groups 62. Each of the groups 62, 63 is in fact a pair of nozzles inthis example.

One of the nozzle pairs 62 will now be described with reference to FIGS.5 and 6. It comprises a first cylindrical nozzle 70 having an axis 71and a second cylindrical nozzle 72 having an axis 73. The axes 71 and 73are generally convergent and are so orientated that they are closest toeach other in a region, generally indicated at 74 in FIG. 5, which is ator just outside the outer cylindrical surface 57 of the piston. Thisregion 74 will be called the mixing region. The two nozzles exit into arecess 75 which is machined into the outer surface 57. The recess is inthe form of part of a cylinder, having a flat end wall 76 containing theouter end of the nozzle 72, and a cylindrical wall 77 containing theouter end of the nozzle 70. The mixing region 74 thus includes the spacewithin the recess 75.

The nozzle 70 is drilled through the piston wall at an angle such thatit is tangential at its inlet end to the bore 82 of the piston barrel54, in the manner indicated at 80 in FIG. 6. A longitudinal plane 83containing the axis 71 is therefore orthogonal to a longitudinallyextending diametral plane 84 of the barrel 54 which contains the pistonaxis Y, FIG. 3, and which intersects the bore 82 at the point 80. Inother words the angle Q, FIG. 6, is 90 degrees. The plane 83 isintersected by another longitudinal plane 85 containing the axis 73 ofthe second nozzle 72. The angle R between the planes 83 and 85 is 90degrees in this example, but may have a value within the inclusive range40 to 90 degrees.

In the rear set of nozzles 58, all the nozzle axes 71, 73 lie in thediametral plane 60. However, this need not be the case. Indeed, in thepresent example, it is not the case with the front nozzle set 59, inwhich the axes of each first nozzle 90 is offset so as to be skew withrespect to the axis of the associated second nozzle 72, the latter beingarranged in the same way as in the rear nozzle set 58. Thus in eachnozzle pair 63 of the front set, the axis 91 of the nozzle 90 is offsetby an angle S, FIG. 7, from the diametral plane 61 which intersects themixing region 74 and which, in this example, also contains the axis ofthe second nozzle 72. The angle S is 45 degrees in this example, but maybe of any desired value. The axes of the second nozzles 72 may also beoffset so that these nozzles are directed somewhat forwardly, therelevant angle P (FIG. 4) being in the inclusive range 10 to 90 degreesbetween the axis of the nozzle 72 and the bore 82.

When water under pressure is introduced through the rear end of thepiston 50, it is forced out through the nozzles 70, 72, 90. The firstnozzles 70 and 90 are so orientated that the jets of water issuing fromthem set the piston in rotation about its axis Y. The direction of thisrotation is indicated at X in FIG. 6. It will be realised that as thisrotation takes place, the water within the barrel 54 tends to swirl insuch a direction as to be forced tangentially into the nozzles 70 and90.

In addition, some of the water passes out through the second nozzles 72,though at a generally lower flow rate than that passing through thefirst nozzles. The jets issuing from the first and second nozzles ofeach pair impinge on each other in the mixing region 74, thus causing asubstantial amount of atomisation of the water.

FIG. 8 shows a typical application in connection with fire fighting, inwhich the water projected from tile spray gun of the invention is usedas a fire shield. In FIG. 8, the fire is indicated at 32 and the waterfrom the spray gun is again indicated at 47. A baffle 30 is fitted overthe tube I to protect the fire fighter from the water itself.

FIGS. 9 to 11 show typical uses for a modified form of the spray gun,described below with reference to FIG. 12 and having a trepanning drill15 fitted at its leading end.

FIG. 9 shows the use of this spray gun to extinguish a fire in an upperroom 20 of a building, using an extension 21 coupled to an extensiontube 2 and extending downwards to a fire engine or hydrant 22. In thisexample the hole 46 made by the drill 15 is through an outer wall over awindow 23.

FIG. 10 shows the spray gun of FIG. 12 when used for extinguishing afire in a loft 24, by drilling through the ceiling 25 of the room below.

FIG. 11 is a diagrammatic plan indicating a hotel room 26, enteredthrough a narrow passage 27 via a door 28 from a corridor 29. In thiscase the drill 15 is used to drill through the door 28, and the spraygun is attached to a hose 45 through an extension tube 1' of the samediameter as the spray gun body 1. The piston spray head, 3, can thus belocated in the middle of the room 26, so as to distribute water asevenly as possible.

Referring to FIG. 12, the rear end of the spray gun body 1 carries acoupling 2 which is adapted (by means not shown) conventionally forconnection to the leading end of a fire hose, so that water underpressure is introduced into the tubular body 1. The latter has acarrying handle 49. The bore of the body 1 is smooth towards its leadingend, which contains a hollow cylindrical spray head 3, generally similarto the spray head 50 already described with reference to

FIGS. 3 to 7, and adapted as a piston as in FIG. 2. Further Jet nozzles6 may be provided in the front end of the head 3 if required.

The head or piston 3 is coaxial with the body 1, and is freely rotatableon a coaxial shaft 8, itself rotatable and mounted in bearings 9 and 10carried coaxially within the body 1. The shaft 8 is hollow, and open atboth ends. It carries: a coupling 13 at its rear end; means, not shown,for connection to the pressurised water supply: and a nozzle 18 at itsleading end, which projects some way forward from the front end of thebody 1. The shaft 8 carries a thrust block 12, including a furtherbearing (not shown). The thrust block 12 bears against the front end ofthe piston 3. The coupling 13, which is only indicated diagrammatically,is of any suitable kind suitable for coupling the shaft 8 to a drivemeans, not shown, for rotating the shaft 8.

A head piece 14 is secured to the front end of the shaft B, and carriesthe cylindrical trepanning drill 15 having a drill tip 16, coaxiallywith the shaft 8 and extending forward of the Jet nozzle 18. The headpiece 14 may incorporate a stop valve whereby water can be admitted atwill to the nozzle 18, to be projected forward within the drill 15 asindicated at 48. A compression spring 19 is mounted around the shaft 8between the head piece 14 and the thrust block 12. This spring biassesthe piston 3 into the position shown in full lines, in which the piston3 lies within the tubular spray gun body 1 so that its jet nozzles areprotected against blockage by foreign matter.

In the event of fire in an enclosed space, such as a room in a woodenhouse, the drill tip 16 can be placed against a wall of the enclosurefrom outside. The drive means mentioned above is coupled to the shaft 8by means of the coupling 13. For this purpose, a conventional electricdrill of suitable power rating may be used. The shaft 8 is thus rotated,so that the drill 15 drills a hole through the wall, of a diametersubstantially the same as that of the cylindrical body 1. The drill canbe cooled while operating, by means of water introduced through the Jetnozzle 18, and as soon as the hole through the wall is completed, waterwill thereby be applied to the fire inside.

The spray gun body 1 is now introduced into the hole so as to lie withinit, and full water pressure is applied to the rear end of the cylinder 1so as to force the piston 3 forward and out, into the position indicatedat 3' in phantom lines, in which its barrel 4 projects forward out ofthe cylinder 1 to expose the jet nozzles, in the same way as in FIG. 2.

The jet nozzles being so arranged as to cause the piston 3 to rotateabout the shaft 8, water is thereby distributed, within the room, innearly all directions, as indicated diagrammatically by the broken lineenvelope at 47. In addition, the jet nozzles are so arranged that thewater is at least partly atomised. The body 1 can be led into the roomas far as desired, for example by attaching a suitable extension to thecoupling 2 and removing the handle 49.

Because the hole drilled through the wall is substantially the same asthe outer diameter of the tube 1, additional air is not drawn throughtile hole into the room.

The use of the drill 15 is optional, since the spray gun can of coursebe used in situations where it is not necessary to drill through astructural part such as a wall. The head piece 14 can then be withoutthe drill.

Spray leads according to the invention may be used in many applicationswhere a fine spray of water is required to be delivered in anessentially non-directional sense, i.e. substantially all around thespray head as exemplified at 47 in FIGS. 1 and 5. Their use is notconfined to fire-fighting: they may be used in various processingapplications. The liquid sprayed need not be water. Again, if hot waterrequiring to be cooled is discharged through the head, it will berapidly cooled and can then be collected. The spray head can readily beadapted to deliver make-up water to a steam cooling tower or similarinstallation, the spray of water rapidly absorbing heat from the steaminto which it is discharged.

We claim:
 1. A spray gun, comprising:mounting means: a hollow,substantially cylindrical body having an upstream end adapted forconnection to a high pressure liquid supply and a downstream end whichis open and provided with said mounting means; and, a spray head forconverting high pressure liquid into an enveloping atomized spray mistaround said spray head, wherein said spray head comprises a hollowcylindrical shell having a barrel portion of circular cross-section,said mounting means mounting said spray head for rotation about itslongitudinal axis, said spray head and said hollow body havingcooperating bearing surfaces for sealing said spray head to said hollowbody while permitting rotation of said spray head about its longitudinalaxis, said spray head having means substantially closing saidcylindrical shell ahead of said barrel portion and having an upstreamend which is open for receiving high pressure liquid from within saidhollow body, said barrel portion having groups of jet orifices arrangedaround its circumference and formed through its wall, each of saidgroups comprising at least two orifices having substantially convergentaxes orientated so as to be closest to each other in a mixing regionadjacent the outer cylindrical surface of said spray head, the axis ofat least one orifice in each of said groups being orientated in apre-determined circumferential direction for direction a jet of saidliquid in said circumferential direction and for promoting rotation ofsaid spray head about its axis, said outer cylindrical surface having aplurality of recesses formed therein, one of said recesses for each saidgroup of orifices, the orifices of each group opening into therespective said recess whereby said recess consititutes at least part ofthe mixing region associated therewith.
 2. The spray gun according toclaim 1, wherein the orifices of each said group are arranged forpassing liquid through them at different flow rates.
 3. The spray gunaccording to claim 1, wherein said groups of orifices are arranged as aplurality of sets, each of said sets having a plurality of said groupsdistributed circumferentially around said barrel portion of said sprayhead, the groups of jet orifices in one set being offsetcircumferentially from the groups in a next adjacent set.
 4. The spraygun according to claim 1, wherein at least one of said groups oforifices comprises orifices the axes of which are in a skew relationshipto each other.
 5. The spray gun according to claim 1, wherein at leastone orifice has its axis inclined to a diametral plane that intersectsthe associated said recess.
 6. The spray gun according to claim 1,wherein at least one said group of jet orifices comprises a firstorifice orifice and a second orifice, the axis of the first orificebeing substantially orthogonal to a diametral first axial plane so thatthe first orifice is substantially tangential to the bore of the barrelportion.
 7. The spray gun according to claim 6, wherein the axis of thesecond orifice lies in a second plane, the angle (R) between the axis ofthe first orifice and the second plane being in the inclusive range of40° to 90°.
 8. The spray gun according to claim 6, wherein the axis ofthe second orifice is directly forwardly.
 9. The spray gun according toclaim 8, wherein the axis of the second orifice makes an angle (P) withthe bore of the barrel portion in the inclusive range of 10° to 90°. 10.A spray gun, comprising:mounting means; a hollow, substantiallycylindrical body having an upstream end adapted for connection to a highpressure liquid supply and a downstream end which is open and providedwith said mounting means; and, a spray head for converting high pressureliquid into an enveloping atomized spray mist around said spray head,wherein said spray head comprises a hollow cylindrical shell having abarrel portion of circular cross-section, said spray head havinginternal first bearing means supporting said spray head on said mountingmeans adjacent an anterior end of said spray head and external secondbearing means adjacent a posterior end of said spray head and engagedwithin the bore of said hollow body, said first bearing means and saidsecond bearing means sealing said spray head to said hollow body whilepermitting rotation of said spray head about its longitudinal axis, saidspray head having means substantially closing said cylindrical shellahead of said barrel portion and having its posterior end open forreceiving high pressure liquid from within said hollow body, said barrelportion having groups of jet orifices arranged around its circumferenceand formed through its wall, each of said groups comprising at least twoorifices having substantially convergent axes orientated so as to beclosest to each other in a mixing region adjacent an outer cylindricalsurface of said spray head, and the axis of at least one orifice in eachof said groups being non-radial.
 11. The spray gun according to claim10, wherein said mounting means and said hollow body are of such lengthsthat said spray head is movable, under the influence of pressure of saidliquid from its posterior end, axially from a first position,substantially enclosed within said hollow body, to a second positionprojecting axially from said hollow body.
 12. The spray gun according toclaim 11, further comprising spring return means for moving said sprayhead from its said second position to its said first position.
 13. Thespray gun according to claim 10, wherein said mounting means comprisesan elongate support member coaxial with said hollow body and ofsubstantially circular cross-section.
 14. The spray gun according toclaim 13, wherein said elongate support member comprises a hollow tubeadapted to direct some of said high pressure liquid forwardly beyondsaid spray head.
 15. The spray gun according to claim 14, wherein saidhollow tube carries a trepanning drill at its outer end.